Esophageal stents are known that come in a variety of materials including stainless steel, nickel titanium shape memory alloys, and other proprietary alloys. Such stents may comprise a mesh or zig zag configuration and one or more full or at least partial coverings. Implantation is accomplished using a catheter. The catheter may be size 16 French to 28 French, for example. Post implantation diameter may increase to nearly 3 centimeters, for example. For example, WallFlex™ is Boston Scientific brand of esophageal stent, and Evolution® is a Cook brand of esophageal stent. A multiple layer stent is disclosed in U.S. Pat. No. 5,645,559, for example, which illustrates the way that such stents are positioned using a catheter, for example. U.S. Pat. No. 6,302,917 illustrates an anti-reflux, zig-zag stent with a tubular sleeve extending from a tubular frame. The disclosures and drawings of these references are incorporated herein in their entirety for the purpose of showing how such stents are constructed and inserted. Nothing in the prior art shows a practical one-way stent comprising a collapsible sock that does not invert when back pressure increases.